Question about Moen & Posi-Temp Single Handle Shower Or Tub Valve

2 Answers

Moen single handle valve tub/shower

Only hot water cold side no flow Daughter home from college tub /shower in this bath is rarely used. Pulled cover off and checked the flow vave on each side of mixer. both are on , but still no cold water. Could valve be clogged. Cold water in sink and commode are OK

Posted by on

  • 4 more comments 
  • Anonymous Mar 14, 2014

    Still get hot water but the flow is greatly decreased as the cold water is diverted through this plastic tube

  • Anonymous Mar 23, 2014

    My Moen is a T21520RB

  • Anonymous Mar 23, 2014

    The almost new Moen shower valve is difficult to turn completly off

  • Anonymous Mar 30, 2014

    should cold water flow through the mixer (index Button Cold/hot) only hot water flows Is this corrected by adjusting anti scald valve?

  • Anonymous Mar 30, 2014

    We have no cold water flowing through the index Button Cold/hot mixer area of the Oak Brook 48011 shower/tub 2 handled Faucet Assembly Will adjusting the anti-scald valve correct this

  • Anonymous Mar 31, 2014

    shower temperature doesnyt adjust shower is too hot but occassionally it also goes cold



2 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 14 Answers

The Moen Posi-Temp Valve is a pressure balanced valve and when not used for long periods of time they can stick causing only cold or hot water to pass through the valve.
A New Posi-temp cartridges can be purchased at most plumbing supply houses or big box outlets such as Lowes or Home Depot.
As long as you had cold water before, a new cartridge will solve the problem. In the future it would be wise to occassionally operate the valve at least a couple of times a month in order to keep the pressure assembly from becoming lodged in position. Just follow the instructions included with the new cartridge on the proper removal of the old cartridge and the installation of the new cartridge. a little silicone grease inside of the valve before installing the new cartridge will also help.
Be sure that there is no particles of the old cartridge left in the valve.

Posted on Dec 27, 2008

  • ed brown Nov 04, 2010

    Moen used to recommend the use of silicone grease but no longer. Two problems which have arisen over the years - silicone grease can find it's way - even in small amounts into the internal valve spool. When that happens it will cause the valve to cease proper operation. Second, if you apply silicone grease to the Moen cartridge it will usually cause the flat external cartridge seals to bind up to the point that the cartridge will become almost impossible to remove.

    What happens is the grease, even in small amounts, will cause the seals to catch or bind on the water inlets inside the valve body and when that happens you will have to use a huge force to later remove the cartridge the next time. Sounds funny but this grease is sticky.

    The last job I had, 3 cartridges in a row with silicone grease bound up and were non-removable, except with the claw end of a claw hammer. When all grease was removed from the next cartridge and the valve bore, the cartridge seals did not hang on the valve body.

    If you view Moen's latest instructions, ver 'H', they have removed the suggestion for grease.

    There is no reason to ever buy a Moen cartridge. They will give them to you for free if you call their 800#.

    Before inserting any Moen Positemp cartridge, shake it from end to end first. If you do not hear the spool move - do not install it. Instead you can disassemble it and clean the spool, or just install another new cartridge. If the spool is not moving freely, it will not work properly.


  • Level 1:

    An expert who has achieved level 1.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 4 Answers

The spool valve, not the cartridge, causes this. It is the large plug with a screwdriver slot just to the right of the main control handle and cartridge.

Posted on Feb 07, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Why does moentrol bath valve give hot water pointed to "C" and vice versa?

Easy one.
Feel the pipes. The pipe on the right should be cold. If the pipes are correct, turn the cartridge 180 degrees.

Jan 20, 2013 | Moen & One Handle Tub & Shower Faucet

1 Answer

Moen Kingsley Moentrol single handle bath/shower fixture. Had guests use this recently and they only could get hot water. When you turned the handle to cold nothing comes out. Only hot when turned the...

Sounds like the cause of your problem is the pressure balancing spool. Call Moen at
and explain the problem. They will send a repair part to you free of charge. the link below is a "blow up" of your valve.

Mar 10, 2011 | Moen & One Handle Tub & Shower Faucet

1 Answer

Moen Shower Valve Model L82839 installed: Water comes out of shower head when running bath. Thanks.

Only two possibilities here the diverter tub spout is not open all the way to let water to the tub only or the shower valve is installed up-side-down.

Mar 06, 2011 | Moen & Posi-Temp Single Handle Shower Or...

3 Answers

I've been given an old (10+ yrs) Moen shower control valve that I want to use (it does apparently have pressure balancing built-in), but don't know which side is hot and which is cold. Does Moen always...

Moen and all shower valve manufacturers follow american federal guidelines. Hold the unit in your hand with the handle facing you - the left side is the hot water inlet and the right side is the cold water inlet.

Nov 25, 2010 | Moen & Posi-Temp Single Handle Shower Or...

1 Answer

Please Help! I installed 3 Moen Banbury single handle faucet/shower units. Water will not flow from either the hot or cold handle position from any of the units. I pulled a feeder pipe (pex) off each one...

were there any thread protectors inside the hot and cold inlets? sometimes they put Styrofoam pieces inside to keep debris out of the inlets and outlets. inspect inside of valve body through inlet holes thoroughly

Sep 16, 2010 | Moen & One Handle Tub & Shower Faucet

1 Answer

We have a home that is 3 years old. We never used the 3rd bathroom shower until today. We have a Moen single knobe shower/bath valve. To get water from the faucet you pull the knob out. To adjust the...

Remove handle to gain acess to the temperature limit stop. Remove handle and pull out handle adapter kit and next there is a dail that can be adjusted to control the water to balance the temp. It could have been installed wrong, pay attention to where it is now and pull it back to it disengages out of the stem and move it counter clockwise a little and reinstall. Put handle on and test water for correct movement.

Go to link below for a part's diagram if needed.

TO ORDER PARTS CALL: 1-800-465-6130

Aug 15, 2010 | Moen & Posi-Temp Single Handle Shower Or...

1 Answer

No cold water coming out of bath/shower, only really hot water

Is it a Delta brand, single handle valve? If so, chances are you need a new "stem" and can be purchased at any plumbing suply store or home store. You will need to shut the water off to the house to do this (unless you are certain you know where the shutoffs are). Good luck

Sep 02, 2009 | Moen & One Handle Tub & Shower Faucet

1 Answer

Replaced a moen cartidge and now the water is not hot in shower

make sure when you turn on the hot and cold shut off valves all the way and turn the moen on after that. Some times I would get that problem if I turned one(either hot or cold) off then tried the shower.

Feb 23, 2009 | Moen & Posi-Temp Single Handle Shower Or...

1 Answer

Single handle moen bath fixture only lets out hot water

remove the cartridge and see if their is anything blocking the cold inlet.If you dont see any dirt than that means that the cartridge needs to be replaced

Jan 23, 2009 | Moen & Posi-Temp Single Handle Shower Or...

Not finding what you are looking for?
Moen & Posi-Temp Single Handle Shower Or Tub Valve  Logo

1,502 people viewed this question

Ask a Question

Usually answered in minutes!

Top Moen Home Experts


Level 3 Expert

4356 Answers

john h

Level 3 Expert

17350 Answers

Andrew Bugbee

Level 2 Expert

259 Answers

Are you a Moen Home Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides